1. Field of the Invention
The present invention relates to a suction device used in the production of a microwave tube, and more particular to a suction device that can greatly save the vacuum suction time of aging process and therefore reduces the cost associated with the production of a microwave tube.
2. Description of the Related Art
With reference to FIG. 11, a conventional suction device used in aging process of a microwave tube (70) includes two ion pumps (71 and 72) respectively connected to two distal ends of the microwave tube (70). In an aging process of the production, the ion pumps (71 and 72) suck air from the microwave tube (70) until the pressure in the microwave tube (70) reaches less than 10xe2x88x929 Torr to create a substantial vacuum state. However with the today""s technical standard, the sucking procedure mentioned is time-consuming and therefore results in a high cost associated with the production of the microwave tube (70). Taking the typical 2 liters/sec capacity of the ion pumps (71 and 72) as an example, the aging process time under the specified conditions is as following:
1. DC aging (0%xcx9c11% duty): at least 70 hours;
2. RF aging (0%xcx9c11% duty): at least 150 hours; and
3. RF aging (11% duty): 50 hours.
Theoretically, if the ion pumps (71 and 72) are adapted to have a higher capacity ( greater than 2 liters/sec), the aging process time can be reduced. However ion pumps having high capacity are still very bulky and massive. In addition to these practical drawbacks in operation, they also increase production cost of the microwave tubes.
Accordingly, the present invention tends to provide a suction device used in the aging process of a microwave tube to mitigate or obviate the aforementioned problems.
The objective of the present invention is to provide a suction device used in the production of a microwave tube to save the aging process time and the cost associated with the production of the microwave tube. The suction device has an ion pump connected to an electron gun and a suction unit connected to a collector, wherein the electron gun and the suction unit are located in opposite ends of the microwave tube. The suction unit has a barrel communicated with the microwave tube, and a getter disposed inside the barrel and electrically connected to an electric power source in order to absorb air in the microwave tube.